Vertebral artery hypoplasia is a congenital anatomical variation characterized by underdevelopment of the vertebral artery.
The prevalence of hypoplastic vertebral arteries is reported to be 2-6% from autopsy and angiograms 1.
These are an asymptomatic anatomical variation in healthy people and there are no signs of vertebrobasilar insufficiency, even among patients with pronounced asymmetry 2.
There is no clear consensus on the definition of the hypoplastic vertebral artery, but is defined by some authors as 2:
- vertebral artery luminal diameter < 22 mm
- vertebral artery volume flow <30-40 mL/min on color duplex ultrasonography
Individuals with hypoplastic vertebral artery are more likely to develop inferior cerebellar artery or lateral medullary infarction.
Healthy subjects presenting this condition demonstrated abnormal vestibular evoked myogenic potential 3.
- vertebral artery dissection
- vertebral artery ostial stenosis
- 1. Chuang YM, Chan L, Wu HM, Lee SP, Chu YT. The clinical relevance of vertebral artery hypoplasia. (2012) Acta neurologica Taiwanica. 21 (1): 1-7. Pubmed
- 2. Park JH, Kim JM, Roh JK. Hypoplastic vertebral artery: frequency and associations with ischaemic stroke territory. (2007) Journal of neurology, neurosurgery, and psychiatry. 78 (9): 954-8. doi:10.1136/jnnp.2006.105767 - Pubmed
- 3. Chuang YM, Chen CC, Lin CP. Vertebral artery hypoplasia may contribute to abnormal vestibular evoked myogenic potentials. (2009) Acta neurologica Taiwanica. 18 (2): 113-7. Pubmed